Catalytic processes



July 2, 1946. -s. H. MoALLlsTER ETAL v 2,403,107

GATALYTIC PROCESSES Filed Jan. 3, 1944 2 Sheets-Sheet l bq Their AH'of-ncgt Z% &d

S. H, MCALLSTER ET AL l CATALYTIC PROCESSES July 2, 194s. 2,403,107

Filed Jan. l3,* 1944 2 sheets-sheet 2 I5 A n I4 lnvzmors; Sumner H. McANs+cr q.John Anderson William E. Ross Patented July 2, 1946 CATALYTIC PROCESSES Sumner H. McAllister, Lafayette, and, John An` derson and William E. Ross, Berkeley, Calif., assgnors to Shell Development Company, San Francisco, Calif., a corporation of Delaware Application January 3, 1944, Serial No. 516,832

or contact materials comprising metal halides and relates more particularly to catalytic hydrocarbon conversions executed lin the presence of `metal halides of the Friedel-Crafts type. A

particular aspect of the invention relates to-the production of branched chain saturated hydrocarbons from hydrocarbons comprising saturated hydrocarbons of straight chain or less branched chain structure.

Metal halides find application as catalysts or contact materials in many processes comprising those directed to the conversion or treatment of hydrocarbons. The manner in which these metal halides are employed varies in accordance withl the particular process in whichl they are used. They may be used in solid formnin which the size of the individual pieces may range from relatively large chunks to finely divided form. When used in the latter form lthey may be em- Dloyed in combination with any of the many available carrier materials or as a suspension in liquid or gaseous media. In other processes they are used in the molten state functioning as catalysts, as diluents, as carrying media for reactants or other catalytic materials, or merely as means for imparting heat to, or withdrawing heat from, reactants or catalysts by direct contact therewith. In still other processes they may be utilized in the vapor state. Of the metal halides those of the Friedel-Crafts type are particularly favored` because of their ability to function as catalysts for a great number of differing catalytic reactions wherein their degree of activity can be modified to attain particular results undery specic operating conditions. These processes may employ a single metal halide or a mixture of two or more metal halides. Certain processes use the metal halide in a modied form, obtained,

for example, as a reaction product resulting fromi the interaction of the metal halide with a suitable organic compound comprising, for example, a suitable olenic, aromatic, naphthenic or even parainic hydrocarbon.

The degree to which the metal halides dissolve in hydrocarbons with which they arel brought into contact during the process, as well as the ease with which they volatilize or sublime, will vary considerably depending upon the particular metal halide or mixture of halides, the nature" and composition of the reactants and the operating conditions employed. The greater part of these compounds, particularly those of the :l 17y Claims.4 (Cl. 2260-0835) treatment orv con,-

these characteristics to a suflicient degree to render diiiicult, if not impossible, the complete avoidance of `entrainment of small amounts thereof from the reaction zone together with the product stream. By the term entrainrnent as used throughout this specication and claims is meant any removal of metal halide from the reaction zone (and/or, in the case of liquid phase operation, from a catalyst separator comprising `the type wherein catalyst is separated from reactants by stratification) together with the reactants regardless of Whether such removal be caused by physical entrainment, solution, volatilization, sublimation, or any other method by which migration from the greater catalytic mass may be effected. Use o f the catalyst in a'finely dividedustate, the admixture of gaseous materials to the reactants and certain operating conditions,

such as elevated temperatures and rapid throughput rates, variations in pressures, etc., contribute considerably to increasing the normal rate of entrainment generally encountered in the greater number `of processes utilizing the metal halides as contact or catalytic materials.

Though the amount of metal halide so entrained from the reaction zone may appear from casual observation to be a relatively small and therefore an unimportant factor, it nevertheless is a major problem in processes utilizing these materials in the reaction zone and often results in diiiiculties deterring practical operation of a process. Thus, in processes utilizing a metal halide of the Friedel- Crafts type, such as, for example, aluminum chloride, the presence of the metal halide in the reactor eflluence in such relatively small amounts as, for examplaabout 0.01%, seriously impairs eiiicient large scale operation of the process in the absence of means for the substantially, complete removal of the entrained compound from `the product stream prior to its passage into a,

subsequent product separating zone comprising fractionating systems. Such small amounts of j entrained metal halide, even though in the presence of a suiiicient amount of hydrocarbon to effect their solution under normal conditions, still result in serious fouling of heat. exchangers, condensers, reboilers, and other parts of the equipment. They seriously interfere with normal operation of pumps, valves, control mechanisms,

aration of these traces of entrained metal halides Friedel-Crafts type, possesses one or several of 5s from the product stream have often been cumbersome and costly. Thoughcertain methods enable substantial removal lof the entrancd material' l .boilers etc.

fromk the product stream', they are nevertheless achieved-to a substantial degree by the passagek of the reactor eflluence throughY beds of porous,

and preferably highly adsorptive, materials. `j

Such methods, though enabling substantial removal of entrained'metal halide from the product stream, possess distinct disadvantages. YComplete removal of the entrained material requires the vuse of large masses of the porous material and consequently cumbersome and costly Iapparatus. 1

cient production of branched chain saturated hydrocarbons from hydrocarbons comprising straight and/or less branched chain saturated hydrocarbons with the aid ofmetal halide catalysts of the Friedel-Crafts type, enabling the more i efficient separation of substantially all traces of entrained metal halide ,from the reactoreiiluence prior to its introduction into a productY separat- ,ing zone.

yAnother object of the invention is to provide an improved process for enabling the more enicient isomerization of parafnic hydrocarbons With the aid of catalysts comprising aluminum halide in the presence of a hydrogen lhalide promoter. Other objects and advantages of the invention will become apparent from the following detailed description thereof.

The method can, furthermore, not Ybe operated the porous mass. Recovery of the separated catalystfrom the porous material is diicult and generally highly impractical. Amore serious disad- Vantageof such methods resides inthe fact that, notwithstanding intensive dehydration of the adsorptive material, its use in plant scale operationv is, nevertheless, generally accompanied by a release of a still sufficient amount of Water-from continuously and requiresperiodic replacementiof the adsorbent during the course of operation to` Y result not only in serious A'corrosion in subsequent pieces of apparatus,'particularly when hydrogen halides are present, but in making necessary such steps as thev drying oi recycle streams prior to their return to the reaction zone. When hydrogen halide is one of the products to be recycled,`

and must'be introduced into the reaction zone in the anhydrous state, the removal of traces of water therefrom is not only diicult but exceedingly costly. Introduction of additional liquid hydrocarbons into the reactor affluence for the purpose of dissolving the entrained metal halide; such as, for example,'anialuminum halide; during its passage through the remainder of the system, does notv of itself avoid suchV difficulties as the fouling of heat exchangers, condensers and re-y Attempts to concentrate the en" trained metal halide'in one of the fractions separated during the course of a fractionation directed to the separation of the product stream into ultimately desired fractions are, of course, distinctly undesirable not only in that they render diiicult efficient operation of such fractionating system but entail the operating and corrosion difficulties above-referred to in relatively costly and extensive portions of the apparatus. y

Itis 4an object of the invention to provide an improved process for the treatment or conversion of hydrocarbons with catalysts or contact materials comprising metal halides wherein the above difliculties are obviated and complete removal of any substantial traces of entrained metal halide from the' reactor eifluence is effected efiiciently in a simple continuous and uninterrupted step within the process prior to subjection of said reactor eflluence to any substantial degree of fractionation. l v 1 AnotherY object ofthe invention is to provide a process for the more eicient treatment or conversion of hydrocarbons with the aid of metal halide catalysts of the Friedel-Crafts type, en-

abling the substantially complete separation ofy entrained metal halide from the reactor eluence prior to introduction of said reactor effluence into a product separating zone. Y Still another object ofthe invention is the provision of an improved process for the more ef- In accordance with the invention hydrocarbons comprising a hydrocarbon, or mixture of hydroconditions. Eilluence from the reaction zone,

comprising hydrocarbons and entrainedfmetal .l halide, is introduced intoY an entrained 'metal f halide separating zone at an intermediate point thereof. In the entrained metal halide separating zone the reactoreluence is contacted in the vapor state with'a countercurrent stream of a controlled amount of cool hydrocarbons to condense substantiallyv all traces of the entrained metal halide in the absence of any substantial condensation of hydrocarbons. Vapors comprising hydrocarbon reaction products free of any substantial trace of metal halide, and liquid comprising substantially all of the metal halideintroduced into the entrainedl metal halide separating zone are separately withdrawn therefrom. It has been found that the amount of cool hydrocarbons which must be contacted with the hydrocarbon vapors to effect substantially complete removal of entrained metal halide therefrom under these conditions is relatively small compared to the Volume vof hydrocarbons treated. The cool hyn entrained metal halide in the absence of any substantia1 hydrocarbon condensation. Vapors eliminated from the entrained metal halide separatingy zone, now free of any substantial trace of entrained aluminum halide, are passed to a fractionating zone wherein separation' of desired fractions isV effected. In a preferred modification of the invention a heated hydrocarbonl stream, preferably obtained within the system Vas described more fully below, is introduced into thelower part of the entrained metal halide separating zone. Liquid, comprising separated metal halide, withdrawn from the entrained Ymetal halide Vseparating zone is passed inV partl or in its entirety to the reaction fzone.

The rprocess of the invention is applicable to the execution of a Wide 4Variety ofgcatalytic hydrocarbon conversions and treatment"effectedv prising metal halides.

with the aid of catalysts or contact agents com- However, in order to set forth more fully the nature of the invention it will be described in detail herein in its application to the production of branched chain hydrocarbons from hydrocarbons 'comprising straight chain or vless branched chain hydrocarbons, with reference to the attacheddrawingswherein:

Figure I shows a more or less ',diagrammatical elevational section of one form of apparatus suitable lfor the execution, in accordance with the invention, of the liquid phase' isomerization of hydrocarbons with theaid of fiuidtype metal halide catalysts, l

Figure 'II shows a more or less diagrammatical elevational section of a modification of the apparatus of Figure I adapted to the isomerization of hydrocarbons in the Avapor phase with the aid of solid metal halide catalysts. Y Y i Referring toFigure'I of the drawings, an isomerizable saturated hydrocarbon, for example, butane, substantially free of moisture, is forced by 'means of pump I through `line 2 and indirect heat exchanger 3 into a reaction zone. In passing through indirect heat exchanger 3 the butane is heated to a, temperature sufficiently high to maintain Y the desired temperature conditions withinthe reaction zone. Heating means replacing. or complementing heat exchanger 3 comprising, for example, a suitable type of Ahydrocarbon fluid rheating furnace may be used. The reaction zone may comprise any suitable reactor enabling efficient contact between hydrocarbon reactants and the catalyst, for example, a reactor 4 of the mixer type provided with suitable stirring means 5 and valved lines I and 8 for inlet and outlet respectively of catalyst. The reactor preferably comprises suitable insulating means and a, jacket 6 `through which a fluid capable of adding or withdrawing heat from the reactor may be passed. Though but one such reactor is shown in the drawings, two or more such-areactors, arranged in series or in parallel, may suitably be used.

Within reactor 4 butane is contacted with a suitable fluid, metal halide-containing catalyst` comprising a metal halideof the Friedelf-Crafts` type. A wide variety of metal khalide'isomerization catalysts. comprising molten salt mixtures may beused. A particularly suitable catalyst comprises, for examplefa'molten'mixture of antimony trichloride and aluminum. chloride in thef 1 approximate proportions of about 76 to 97 mol percent SbCls and about 24 to 3 mol percent AlCla. Although a catalyst comprising aluminum chloride and antimony trichloride has been ,I 6 for example, a temperature in the range lof from about 60 C. to about 150 C., `depending uponI the particular catalyst used. The .pressure inkreactor 4 may vary from the minimum pressure the hydrocarbon feed, flowing through line 2, by`

means of valved-line 9. The'amount,l of hydrogen chloride introduced into the system may vary in accordance with the nature ofthe charge, the catalyst composition, and the operating con- ,ditions,` and may range, for example, from` about .03% to about 25% of the butane charged. If

desired, inert gaseous materials comprising'hydrogen, nitrogemmethane, CO, CO2 .and hydrocarbons other than those Abeing isomerized,y may be added to the hydrocarbon feed for thepurpose of suppressing undesirable side reactions, diluting the charge or aidinginthe introduction of heat into the reactor. v i a From reactor 4 the .hydrocarbon kreactants comprising admixed hydrogen halide andentrained catalyst are passed into a preliminary catalyst separating zone whereinseparation'of` a hydrocarbon layer fromya catalyst layer is effected by stratiiication. The preliminary separating zone maybe separatefrom reactor 4 and provided with means for the recycling ofthe catalyst layer to the reactor, or it may be comprised Within the reactor itself a's is the annular preliminary separator I0 of reactor 4. Thehydrocarbon layer comprising isobutane, normal butane and hydrogen halide yis removed from` the annular separator I0 throughlineII.

Regardless of the time of residence oft-he hy drocarbon layer in, the preliminary separating zone, it will generally comprise a certain amount of entrained catalyst components. The more sol uble' of the, catalystl components `will,generally predominate. `:Inlthe present illustrative descriptiOn'of the invention` the antimony trichloride will exceed the aluminum chloride entrained `by the hydrocarbon stream. owing through. LlinemII. Heating means, for example,` indirect heat-;ex-

changerv I2 as well as a valve I3 `are present in `line III. By means of the heat 'inputv ,intov heat Vexchanger I2 or by` suitable reduction of preschosen as the preferred catalystgi'n the present 'illustrative description of the invention, it is to be understood that the invention is in no wise limited to the useA of a catalyst containing any particular metal halide or any particular mixture of metal halides possessing the ability to isomerlze 1 hydrocarbons. Thus, suitable catalystscomprise molten mixtures of a halide of aluminum in admixture with one or more halides of one or more of the following, Li, Na, K, Cu, Mg, Zn, Cd, Sn,

' pb, sb, As, 131,01*, Mo, Fe, co, Ni, etc.v suitame s fluid-type catalysts also comprise those of the organo-metal halide complex type obtained by the interaction under suitable conditions of a metal halide and a suitable organic compound.

The temperature to be maintained Within re-V y actor V4- may range from the minimum temperature at which the catalystfcan be maintained in the fluid state up to approximately 200 C. A

1 particularly effective temperature may comprise,

sure in passing through valve .I3 or by' bOthof these expedients, the hydrocarbon streamv is caused to vaporze to at lleast a substantial del gree, .and is then passed'into an entrainedvcataf lyst separating zone. The entrained catalyst separating zone may comprise a chamber, or column, I4, at least a portion` of which is provided lwith suitablerpacking material I5 suchas, for

example,.Raschig rings, quartz chips, silica stone,

etc., or several bubbletrays. A suflicient amount of a cool hydrocarbonstream, for. example, Vbutanes, is introduced into the upper part of .col-l umn I4, through line I6, at a temperature at, and preferably below, the bubble point of the hy drocarbon feed to the column, to bring about the separation of Ya liquid fraction'comprising substantially all of theentrained catalyst components 'from a vaporffraction comprising' isobulV of any substantial trace of metal halides.

Conditions'within vcolumn. I4 as 'well as V,the

" tanes passed therethrouglfigV Y 'i columnM. 'Additional'coolingpmeans n lin the vdrawings-rnaybe' provided -to Aeii'ec't further cooling lof-thehydrocarbon stream flowing 33 into lineV 9.

Y`amountpf Ycool hydrocarbons .introduced .into the v tcpfthereormay vary within the scope offthe` invention depending to some degreeuponxthe lparticularcatalyst used and the .amount of 'entrainment encountered.. .The amount of cool hifi drocarbons introduced into column-.I4 is, howeverr carefullyV controlled .so `as not to exceed the quantity required to effectsubstantially. .com-

` y plete 'condensation of the entrained metal'halides inthe absenceor ani7V substantialcondensation. of butanes. `Underthe conditions of thepresent illustrativedescription of the.. .invention .it

` 'f been found that the introduction of cool .butanes in anamount o'f .from about 0.1 to about 0.2 :percent by volumeof the amount 'ofY hydrocarbon :va-

pors Vtaken: overhead results in the reduction of SbGla ing-the Vapor-fractionftolesg than-0.001%

by weight and AlClsk-toranarnoun'tlto'o lsmallto Y* be detected. In extensive plant scale .isomerization of :butane-with an .illCla-SbChV catalyst, wherein the feed 4to column |11 was at about Wl C., the Vtoptv and bottom temperatures of thecolumn were about 58 C. anda? C.; respectively,` and condensed butanes at a temperature :of Vabout 35 C. were introduced into the upper part oi'.

the column at the rate of about 0.2 percent by vvolume of the hydrocarbon overhead of the loolvapor overhead umn, the SbCls content'of Ythe i the AlCla convwas less than about 0.001% and tent too 'smallto -beA detected. "The liquid .removed from the bottom of column .|4. consisted of about V98.5%Y eben and about 1;5'%.A1e13 by weight.

The vapor fraction is passed from column '|ll, through line A|9 and cooler v20, into an accumulator 2|.l In Apassing through cooler 20 the 'stream -is cooled tov a temperaturesufciently low to condense at least a substantial part of the bu- Liquid is drawn fromaccurnulator 2| by means of pump A23 and forced throughline's 24 and 25 into 'a-Stripping column 26. A portion of the hydrocarbons, drawn from"- accumulator 2| through line 24,'is passed into lineV I6 to provide the -coolhydrocarbon'streamiintroduced -into .the upper partl of .notfshown through line it. A-valved line 211s provided for the introduction ofhydrocarbons from an'jout- YSide sourceinto line'l. Vapors and gases comprising hydrogen chloride rmay be drawn from accumulator 2| through line '28 to a compressor 29.' From the high pressure side of `compressor l A29 the compressed streamlis vpassedfthrou'gh lineY v3|) into stripping column 26.

Within stripping column 26 a gaseous fraction comprising :hydrogen chloride i's separated `from a liquid fraction comprising isobutane and 'nor- "mal butane. Arhig'h-pressure, forexarnple,V in:Y

Yexcess vof from about 300 pounds, is preferably maintained within'column 26 to aidn effecting the. ydesired separation.' 'The gaseous fraction comprising hydrogen chloride- .is eliminated from f the top of column 26 through valved'line32 and.V-v

f iss in the bottom part thereof, and suitabieicoqie thereof.

aeoaiov ias Y f y ing means suchas, for example, a cooling coil' 3,9

.inthe upper Lpart thereof. Withinfractionator 31 .a vapor fraction comprising isobutane is separated.' from a liquid fraction comprising normal -A butane.

Liquid comprising normal butane is withdrawn from .fractionator 31, through valved line 40 and #eliminated from thesystem or forced in part or in its entiretythroughvalved'line 4|,

A by'v means of pump 42, into line 2.

iVapors comprising isobutane are withdrawn o'verheadirom `fractionator 31 throughvalved line 43 asa final productmandpassed ,to conventional condensing and recovery means.

Liquid is withdrawn from column I through line 44 and is recycled in part or in its entiretyr through Vvalved lines l5` and 41 to reactor 4. Operation' of column I4 withinthescopeofr-the. in-

-vention may comprise -thepresence offlittle,if

any, accumulation aof liquid in -theglowerfpart 'In general, '..howevenitisV preferred to vconduct'tl'le operation with azsubstantial accumulation of liquid'in the lower partei the column. 1

The relatively low melting temperature-oiv SbCla will result in the stratification ofthe accumulated liquidinto anrupper hydrocarbon layer anda lower catalyst layer consisting orgsbCl's ,containing AlCls dissolved therein.l A closed heating coil 46 is provided in the lower part of the: column to enable lrevaporizationof the hydrocarbon layer. Liquid withdrawn rthrough line 44 will then comprise essentially only SbCla and AlCla Vin* the molten state. With the use of the above preferredl AlClx-SbCla catalyst, the liquid so withdrawnwill generally comprise from r1 to about 10 percent, land moreoften not more than about 3 percent by Weight, v'of AlCla. y

When utilizing a catalyst containing.' no usubstantial amount of such low-boiling catalyst com- Vponenu-or none at all, for example, avcatalyst consisting predominantly of only AlCla, the bottomsrwithdrawn from --column I4 will comprise the entrained -catalyst in suspension, or solution, in butanes. The iamount of butanes thus withdrawn as a liquid fraction from ,column Y`lll Vwill generally comprise but fa small portion,lfor ex- Vample, notfmore than'rabout 4%- of thebutanes charged 'tocolumn ld. @When thus `witlulrawing liquid comprising butanesfcontainingthe separated entrained catalystiirom column I4, it may be rreeycled'to the `reaction zone or passed infpart or in its entirety from line' 44, through valved line 41 to a treating zone." The treating'vzonemay comprise any type of suitable equipment enabling 'the separation of metal halides from the hydrocarbon'stream'. The treating zone is diagrammatically represented in the drawings .by means of treating tank 50 provided with suitable means for introducing and recycling therethrough' suit- .able treating agents, means for withdrawing spent treating agents comprising separated metal `halides therefrom, etc.

' v.lill and will depend to some degree upon the parbutanes now free of any substantialv traces ,ofA

, ticular metal -halide or halides present.: ,Thus

when the halide lcomprises' essentially. only antimony trichloride, the fraction may simply be subiected to water-washing and the resultingpiecipitated antimony compounds separated therefrom.

If the metal halide consists .essentially of Aalumilnum chloride, ythe fraction may be treated with a caustic solution to effect neutralization and removal of the aluminum chloride. The resulting hydrocarbon stream, comprising iso and normal metal halides,'is eliminated from treating tank .50

through valved' line 5| andV passed in partorlin The invention is in no wise .hunted to the treatment employed within tank 9y its entirety through valved line 52 ator 31. Y Y y In order to aid in eiiecting the desired separation within column I4y and particularly to elect the elimination of substantially all dissolved hydrogen chloride from the liquid fraction separated therein, a part of the hydrocarbonsk drawn from stripping column 26 through line 36 is passed through valved lines 53 and 54 into the lower part of column I4. If desired, a partor all of the hydrocarbons `thus introduced into column I4 through line 54 may comprise a portion of the normal butane recycled .through line 4I.` -The hydrocarbons are introduced into the lower part of column I4 at a temperature equal to or slightly above their vaporizing temperature, to the attainment of which a heater 55 is provided yin line 54.

.A modiiication of the apparatus shown in ,Figure I, suitable for the execution of hydrocarbon isomerizations in the vapor phase with the aidy of solid type metal halide catalysts in accordance with the invention, is shown in Figure II wherein al1 parts of apparatus identical with those of Figure vI 'have been indicated with like reference characters. The apparatusof Figure II differs mainly from that of Figure I in the nature of the reaction zone, the type of catalyst therein and in the presence of a two-stage cooling system for the vapor overhead from column I4.

The Ahydrocarbon to Ebe isomerized. for example, normal butane, flowing through line 2 in admixture with `added hydrogen halide, for example, hydrogen chloride, emanating from line 9, is vaporized in passing through indirect heat exchanger 3 and passed through. a suitable reaction zone, for example, an enlarged chamber 60 containing a solid type ,aluminum chloride catalyst. Although aluminum chloride has been chosen as the preferred catalyst, suitable isomer@ ization 'catalysts comprise any 'of the .metal halides of the Friedel-Crafts type. The catalyst may beemployed'per se, in lumps. or maycomprise the catalyst in VAadmixture with suitable inert material. vThe catalystV may comprise c a metal halide in nely divided .form supported upon suitable carrier material preferably of a porous nature. A particularly advantageous type of catalyst'comprises a halide of alu1ni'numfor example, aluminum bromide and/or aluminum chloride, supported upon an adsorptive material preferably of aluminous character such as, for example, activated alumina, bauxite.. etc. The temperature in reactor. S may range from about 20 C. toV about 350"` C., ldepending upon the ma-n terial treated and the particular vcatalyst used. With the ,use `of aluminum chloride-containing catalysts temperatures in the range of from about 50 C. to about 150 C. are somewhat preferred. Any suitable pressure comprising subatmospheric, atmospheric or superatmospheric pressures en-v abling maintenance of at least a substantial part of the reactants in the .vapor phase may be employed.

Reactor effluence comprising isobutane, normal butane, hydrogen ychloride and entrained aluminum chloride is passed from reactor 60 through line II into an intermediate part of the entrained metal halide separating column I4. Within column I4 a liquid fraction, comprising a relatively small proportion of the butanes introinto fractionand hydrogen chloride.

umn I4 is obtained substantially as described above for liquid phase operation; by theintroduction of` cool hydrocarbons in controlled amount into the upper part vof column I4. The temperature and actual amount of coolv hydrocarbon so introduced into the upper part `of the column may vary Within the scope of the inven-l tion. They should, however, be at a vtemperature not exceeding and preferably belowthe bubble temperature of the reactants inthe col--v umn. The rtemperature gradient to .be main tained4 within column I 4 will be governed to some degree by the amountl of` hydrogen `chloridefto, be tolerated inthe liquid bottoms.

In the vapor phase isomerization ',of .butane with the aid of a catalyst consisting of (aluminum chloride deposited uponactivated alumina producing a reactor eilluence containingaboutf '10 C. of superheat and 0.01 mol percent of,l entrained aluminum chloride, maintenance of v.a temperature of about`80 C. in the upper part, and a temperature of about 95 C. in the lower part of column I4 is satisfactory. These conditions, obtained with the introduction into the upper part of the column I4 of liquid butanes at a temperature of .about 50 .0. and `at a rate of about 0.3 mol per molof butane vaporstaken overhead from the column, will result in the production ,of a vapor overhead containing, less than about 0.001 mol percent. of aluminum chlo-` ride. The liquid frac-tion separated in column I4 under these conditions. will representA about 2.5% of the butane vapor, taken overhead land lvwill contain about 0.5 moljpercentof Valuminum chloride and 3.5. mol percent of hydrogen chloride. Y' When the liquid fraction separated in column I4. is recycledl to reactor 50 through lines ,44y and y45, removal 0f the hydrogen chloride from` the recycled liquid bottoms is generally not required. In operating with .a solid or supported type catalyst, it will` be found desirable topass at least a part ofthe liquidaluminum chlorijlee containing fraction. recycled through line,k '45 to intermediate parts. of-Ireactor 60. A valved line 6|,with valved branched lines 62,03 and 64 entering the reactor Gilat intermediate points along the length thereof are provided. Indirect heat exchanger 65 is positioned in line 45 toenable Y maintenance of the hydrocarbon stream iiowing duced into the column and substantially all of the entrained aluminum .chloride introduced into the column'is vseparated froma vapor fraction free of any substantial trace of aluminum chloe rider and comprising isobutane, normal' butane therethrough at ,they desired temperature.

When the aluminum chloride-containing liquid bottoms fromcolumn I4 arenot recycled to the reaction zonek but are passed in part or. in their entirety through line 41 to the treating. zone comprising treating tank :50, it is ,preferred to effect. substantial remova1 of HC1 therefrom'prior to their withdrawal .from column I4. 'Ihisis preferably accomplished as described above by the introduction of a hydrocarbon stream emanating fromthe lower part of ycolumns 42li and/or 31 at a temperature, at or above the dew point ofthe reactants in column I4, into the lower part of the column through line 54. By thus introducing the heated hydrocarbon into the lower part of column Mythe hydrogen chloride content of the liquid bottoms is readily reduced to an amount not exceeding, for example, about 0.01 mol percent. If desired, the liquid'bottoms separated in column I4 may be subjected to a stripping operation in a separate zone not shown in the drawings and the overhead thus produced,

I The desired separation of the entrained aluminum chloride within colcomprising hydrogen halidefreturned' to; column amaro? It is thus seenthatthfe processi. 'rfthe invenm Y tion by enabling the. removal, of substantially all traces of entrained'aluminurn chloride from the reactor eifluence eliminates completely' the' diiiculties' due tok catalyst entrainment'by4 relal tively simple method exceeding'byV far injprac- Y ticality the methods utilized heretofore. 1 l

In a l preferred' modicationfhf n "theL invention l thervapor stream comprising normal butane, isobutane and hydrogen chloridefreeof, any sub-f stantial traces of aluminum chloridejpassing from column i4 to accumulator 2j! is subjected 'to ,aY Y preliminary cooling operationresulting in the` condensation ofvjat least a fsuicient Vamount of l thebutanes' for introduction into the upper part of column l t before lcoolin'gj the.fremainder of We claim as ourv invention:

Y 1. In a catalytic hydrocarbon conversion process wherein saturated hydrocarbons are ctmtacted at conversion conditions With a catalyst comprising a solution of aluminumrchloride in antimony trichloride in a reaction zone and eiiluence :from

tion of,substantiallyv all of said' catalyst compothe streamto.theftemperature to' be maintained in accumulator 2f. Accordingly, the 'vapor stream emanating from colunm i4' is' passed through line I9 and'v preliminary cooler' into` anraccumulating drum IST.'` At least' a part of the liquid is removed from accumulator: drum 6'! throughline 681andfforced by means ofY pumplll through line 69 into the upper part of Vcolumn I4.

Un'cond'ensed vaporsy are' passed from 'accumu-` lator 61 through line TI and cooler T2. into` accumulator zi. Liquid withdrawn from accumulator 61 inexces's of that required for introduction into the upper/,part of column I4 is passed through I,

l'in'e13 intoline Hat afpointV up stream from cooler l12. Y Cooler 112i' may' compriseV anyrsuitable type 'ofVV -cool'ingj and/or Arefi'figerating .means Since 'the maintenance of a temperature consid-l nents in the absence of any substantial condensation of said hydrocarbon reaction products, separately removing vaporscomprising hydrocarbon reactionl products free of any substantial trace of catalyst components andliquid Ycomprising aluminum chloride dissolved in antimony trichloride from said catalyst separating zonecooling said vapors to condense at least a part thereof, passing a sufficient portion of the resulting condensate into said catalystseparating zone to provide said stream of cool hydrocarbons used therein, and passing the remainder of said condensate to said ractionating zone.

2. In a catalytic hydrocarbon conversion process wherein hydrocarbons are converted by conerablyilowerr,than"thatf of the hydrocarhonrinitrodu'c'edinto the upper part of columnY l dis. geinV erallyl maintained within' accumulator 21', conl 2 siderable sav'ing'in cost, and 'substantial unprove-` ment'in" eiciency of operation is, obtained' byv thus effecting'Y a primary ,and Yseparate cooling of a portion of the vapor overhead from column M? toV the temperature suitablefor recycling thereto. A valved line 'Miis provided for the passage of liquid' from accumulator 2l through klines 24 and 14 into'rlineV 69, should thisv be .requiredto supplement the amount Vof' liquid passed through line 69 or to aid in,maintaining,thetemperature ofthelatterstream. Thetwo-'stage cooling of Y theoverhead' is particularlyT advantageous when utilizing*accumulato:` 2|,.to`storewithin the system any' excess of HCI over .that Vrequired vfor recyclingY to lthe reactor Afvalveddine 'Edeis pro-` videdfforfthepassagerfromlineiliintofline 1L .Y `g of anyHCb exceeding the amount required"` forv immediate introduction into the reaction zone.

Althoughthe'detailed-description of the invenl tion has been directed to the isomerization 'of a straight chain prain, it is to be understoodY that theV invention is in no Wise limited in its applica-` tion to the'isornerization of any particular hydrocarbon and Ymay be applied broadly not only to the isomerization of any isomerizable hydrocar Y,ratingfzone to, eect the condensation oisubf,A stantially all of said metal vhalide in the absence tact in admixture with Va hydrogen halide at conversion conditions with a catalyst compris-w ing a metal halide of the Friedel-Crafts type in a Vreaction Zone, reactor eilluence" comprising' hydrocarbon reaction products, hydrogen halide and entrained metal halide is` passed to a frac- 'tionating zone, and a gaseous fraction ,comprising Ahydrogen halide isi separated from a liquid fraction comprising l hydrocarbons inv ,said fractionating zone, the steps ywhich comprise contacting said reactor eiiluenceinythevapor state,y with a countercurrent streamfof a controlled.

amount of cool hydrocarbons` in a catalyst sepa-v of any substantial .condensation of Vsaid hydrocarbon reaction products, separately removing Y vapors comprising hydrocarbon reaction products bon with thev aid of metal halide catalysts but to` any type of Ahydrocarbon conversion operation wherein use is madeof catalyst-s or contact materials'comprising a metal halide.l Such conversion' operations comprise not Aonlyfisomerizatifm but alkylation,` cracking, polymerizationY desulfurization, reforming,V etc., of hydrocarbons or` hydrocarbon-containing materials.

Thisis'a continuationdmpart of cti-pending applicationSerial Number 404,056, led July `25, 1941,'now Patent Ser. No. 2,360,699, issued Oct. 1'7, 1944.

and hydrogen halide. 'freeof any [substantial trace of metalhalide and liquidcomprising hydrocarbons containing Vsubstantially'all of said' metal haliderfrom said catalyst separating Zone;

cooling said vapors to condense atleast a part thereof, passing a. sufficient. portion of the resulting condensate into saidrcat'alyst separating zone to provide said streamV of coolV hydrocarbons used therein, passing the remainder of said condensate to said fractionating zone, and passing a part off, Q

said liquid fraction from 'said fractionating `zone at vaporizing temperature into the lower rpart of saidv catalyst separating zone. l

3. In a catalytic hydrocarbon conversion process wherein saturated hydrocarbons are .converted by contact in admixture with a hydrogen halide at conversion conditions with a catalyst comv prising an aluminum halide in a reaction zone,

reactor eiiluence comprising hydrocarbon reaction products, hydrogen halideV and entrained alumi-num halideis passed to a fractionatingzone,

e and a gaseous fraction comprising hydrogen halide is separated from a liquid "fraction comprising hydrocarbons in said fractionating zone, the steps which comprise contacting said reactoreiiiuence inthe vapor state with a countercurrent stream of va controlled `amount of cool hydrocarbons in a catalyst separating zone to effect the condensa-V n tion of substantially all of said aluminum halide* in the absence of any substantial condensation of said hydrocarbon reaction products, separately removing vapors comprising hydrocarbon reaction products and hydrogen halide free of any substantial trace of aluminum halide and liquid comprising hydrocarbons containing substantially all of said aluminum halide from said catalyst separating zone, cooling said vapors to condense at least a part thereof,- passing a sufficient portio-n of the resulting `condensate into said cata.- lyst separating zone to provide said stream of cool hydrocarbons used therein, passing the remainder of said condensate-tosaid fractionating Zone, and passing a part of said liquid fraction from said fractionating zone at vaporizing temperature into the lower pant of said catalyst separating zone. Y

4. In a catalytic butane isomerization process wherein butane is converted to isobutane by contact in adrnixture with a hydrogen halide at isornerizing conditions with a catalyst comprising an aluminum halide in a reaction zonereactor eflluence comprising isobutane, normal butane, hydrogen halide and entraine-d aluminum halide is passed to a fractionating zone, and a gaseous fraction comprising hydrogen halide is separated from a liquid fraction comprising butane in said fractionating zone, the lsteps which comprise contacting said reactor eilluence in the vapor state with a countercurrent stream of a controlled amount of cool hydrocarbons in a catalyst separating zone to effect the condensation of substantially all of said aluminum halide in the absence of any substantial condensation of butanes, separately removing vaporsV comprising -isobutane, normal butano andV hydrogenhalide Yfree of any substantial trace'of aluminum halide and liquid comprising butanes containing substantially ally of said aluminum halide from saidrcatalyst separating Zone, cooling said vapors vto condense atl least a part thereof, passing a suilicient portion of the resulting condensate into said catalyst separating zone to provide said stream of cool hydrocarbons used therein, passing the remainder of said condensate to said fractionating'zone, and passing a part of said liquid fraction from said fractionating zone aft' vaporizing temperature into the lower partv of said catalyst separating zone.

5. In a catalytic hydrocarbon conversion process wherein hydrocarbons areY converted by contact in admixture with a hydrogen halide at conversion conditions with a, catalyst comprising a metal halide of the Friedel-Crafts type in a reaction zone, reactor eiiluence comprising hydrocarbon reaction products, hydrogenl halide and entrained metal halide is passed through an `accumulating zone into a fractionating Zone, a gaseous fraction comprising hydrogen halide is separated from a liquid fraction comprising hydrocarbons in said fractionating zone, and `a part of said gaseous fraction is passed to Vsaid accumulating zone, the steps which comprise contacting said reactor eiiluence in the vapfor state with a countercurrent stream of a controlled amount of cool hydrocarbons in a catalyst separating zone to eiect the condensation of substantially all of said metal halidein the absence of any substantiall condensation of said hydrocarbon reaction products, separately removing vapors comprising hydrocarbon reaction products and hydrogen halide free of lany substantial trace of metal halide and liquid comprising hydrocarbons containing substantially all of said metal halide from said catalyst separating zone, cooling said vapors' in a rst cooling zone to condense at least a part thereof,`

passing at least a part ofsaid condensate from said iirst cooling zone into said catalyst separating zone to provide said stream of cool hydrocarbons used therein, further cooling the remaining vapcrs'and condensate in a second cooling zone, passing cooled vapors and condensate from said second cooling zone into said accumulating zone, and passing hydrocarbons and hydrogen halide from said accumulating zone to said fractionating Zone.

6. In a catalytic hydrocarbon conversion process wherein saturated hydrocarbons are converted by contact in admixture with a hydrogenhalide at conversion conditions with a catalyst comprising an aluminum halide in a reaction zone, reactor efliuence comprising hydrocarbon reaction products, hydrogen halide and entrained aluminum halide is passed throughan accumulating Zone into a fractionating Zone, a gaseous fraction comprising hydrogen halide is separated :from a liquid fraction comprising hydrocarbons in said fractionating zone, and a part of said gaseous fraction is passed to said accumulating zone, the steps Which comprise contacting said reactor eiliuence in lthe vapor state with a countercurrent stream of a controlled amount of cool hydrocarbons in a catalyst separating Zone to effect the condensationoi substantially all of said aluminum halide in the absence of any substantial condensation of said hydrocarbon reaction products, separately removing vapors comprising hydrocarbon reaction products and hydrogen halide free of anysubstantial trace of aluminum halider and liquid "comprising hydrocarbon containing substantially all `of' said aluminum halide from said catalyst separating zone, cooling said vapors in a first :cooling zone to condense at least a part thereof, passing at least a part of said condensate fromsaid rslt cooling Zone into said catalyst separating Zone to provide said stream ofr cool y hydrocarbons used therein, further cooling Vthe remaining vapors and condensate in a'second cooling zone, passing cooled vapors and condensate from said second cooling zone into said accumulating zone, and passing hydrocarbons and hydrogen halide from said acciunulating zone to said fractionating Zone.

7. 'In a catalytic hydrocarbon conversion process wherein normal and branched chain isomerizable saturated hydrocarbons are converted to branched and more highly branched chain saturated hydrocarbons respectively by contact in admixture with a hydrogen halide at isomerizing conditions with a catalyst comprising aluminum chloride in a reaction zone, reactor ei'luence comprising hydrocarbon reaction products,` hydrogen halide and entrained aluminum chloride is passed through an accumulating Zone into a fractionating Zone, a gaseous fraction comprising hydrogen halide is separated from a liquid fraction coinprising hydrocarbons in said fractionating zone, and a part of said gaseous fraction is passed to said accumulating zone, the steps Which comprise contacting saidv reactor veiiluence in the vapor state `with a 'countercurr'ent stream of a controlled amount oi cool hydrocarbons in a catalyst separating zone to Veilect the condensation of substantially all. of said aluminumchloride in the absence of any substantial condensation of said hydrocarbon reaction products, separately removing vapors comprising'hydrocarbon reaction products and hydrogen halide free of any substantial trace of aluminum hlorideand liquid comprising hydrocarbons containing substantially all, offsaid aluminum separating zone, cooling saidv vapors in 'arst cooling zone to condense at least a partthereof, passing at least a part `of said 'condensate from said rst cooling Zone into said catalyst separating zone to provide said stream of cool hydrocarbons used therein, further cooling the remaining vapors and condensate in a second cooling zone,'passingcooled vapors and condensate from said 'second cooling zone into said accumulating zone, and passing hydrocarbons and hydrogen halide from said accumulating zone to said fractionating zone.

8. In a catalytic hydrocarbon conversion proci ess wherein hydrocarbons are converted by con-v V tact in admixture with a hydrogen halide at conversion conditions with a catalyst comprising a` metal'halide of the Friedel-Crafts type in a reac-` tion zone, reactor eluence comprising hydrocarbon reaction products, hydrogen halide and en` trained metal halide is passed through an accumulating zone into a fractionating'zone, a gaseous fraction comprising hydrogen halide is separated from a liquid fraction comprising hydrocarbons in said fractionating zone, and a part of said gaseous fraction is passed to said accumulating Zone, the steps which comprise contacting said reactor eiiluence in the vapor state with a Vcountercurrent` stream of a controlled amount of cool hydrocarbons in a -catalyst separating Zone'to effect the condensation of substantially all of said metall halide in the absence of anysubstantial con-,

densation of said hydrocarbon reaction products,`

separately removing vapor comprising hydrocar-r bon reaction .products and hydrogenhalide free of any substantial trace of metalyhalidev and. liquid comprising hydrocarbons'containing substantially all of said metal halide from said cata` lyst separating zone, cooling said yvapors in a first cooling Zone tocondense atleast a part thereof, passing at least a part of said condensate from ratingzone toprovide said stream of cool hydroV carbons used therein, further cooling the remaining vapors andcondensate in va second cooling Zone, passing cooled vapors and condensate from Ysaid second cooling zone into said accumulating zone, passing ,hydrocarbonsy and hydrogen halide from said accumulating zone to said fractionating Zone, and passing a part of said liquid'fraction from said fractionating zone at vaporizing temperature into-the lower part of said catalyst sepa- Y rating zone. Y

fraction comprising hydrocarbons in said frac-,

tionatingV zone, anda Ypart of Asaid-gaseous fracwhich comprise contacting said reactor eiiluence v in the vapor state withacountercurrent stream chloride from said catalyst substantial trace of aluminum chloride andliquid comprising hydrocarbons containing substan- V vtally all of said aluminumchloride from said catalyst separating zone, cooling said vapors in a rst cooling zone to condense at least a partV thereof, passing at least a part of said condensate from said rst cooling zone into said catalyst separating zone to provide said stream of cool hydrocarbons used therein, further cooling the remaining vapors and condensate in a second 'cooling zone, passing cooled vapors and condensate from said second cooling zone into said accumulating` zone, passing hydrocarbons and hydrogen halide from said accumulating zone to said fractionating zone, and passing a part of said liquid fraction from said fractionating zone at vaporizing temperature into the lower part of said catalyst separating zone.

u 10. In a catalytic butane isomerization process wherein butane is converted to isobutane by contact in admixture with hydrogen chloride at isomerizing conditions with a catalyst comprising aluminum chloride in a reaction zone, reactor eiiiuence comprising isobutane, normal butane, hydrogen chloride and entrained aluminum chloride is passedthrough an accumulating zone into I afractionatingnone, a gaseous iractioncomprising hydrogen chloride is separated from a'liquid fraction comprising butane in said fractionating zone, and a part of said gaseous fraction is passed `to said accumulating zone, the steps which comsaid first cooling zone into said catalyst-sepaprise contacting said reactor eiuence in the vapor state with a countercurrent stream of a controlled amount of cool hydrocarbons in a catalyst separating zone toeifect the condensation of substantially'all of said* aluminum chloride in the absence of anysubstantial condensation of bu,- tanes, separately removing Yvapors comprising isobutane, normal butanerand hydrogen chloride,

free 4of any substantial" trace ofA aluminum chloride Yand-liquid comprising butanes Vcontaining Asubstantially all of said aluminum chloride from said catalyst separating zone, cooling said vapors Y carbons. charged, by contact at isomerizing Vconditions With aV catalyst comprising ametal halide Y,

Vtion is passed to said accumulating zone, the steps of a-controlled amount of cool hydrocarbons in Y apcatalyst separating zonerto effect the condensation ofV substantially all of said aluminumV chloride in the absence of any substantial condensation u Yof said hydrocarbon reaction products, separately removing vapors comprising hydrocarbon reaction products and hydrogen halide free of any in a first cooling zone to condense atleast a part thereoL'passing at least a part of said condensate Yfrom said rst cooling zone into said catalyst separating zone to provideirsaid stream' of`cool Y butanesused therein, further cooling the remaining vapors and condensate in a second cooling zone, passing cooled vapors and-condensate'irom said'second cooling zone into said accumulating zone, passing butanes and hydrogen halide from said accumulating zone to said fractionating zone, and passing a part of said liquid fraction from said fractionating zone at vaporizing temperature into the-lower part of said catalyst separating zone.

11. 1 In a catalytic hydrocarbon conversion process wherein normaland branched chain isomerizable saturated hydrocarbons are converted to branched and more highly branched chain hy drocarbons respectively, havingfth'e same number oicarbon atoms to the molecule as the l'iydrokof the Friedel-Crafts type in a reaction zone and eiiluence from saidr reaction zone 'is passed to a fractionating zone, the steps-which'comprise con-l tacting said reactor eiiluence comprising hydrocarbons and entrained metal'halidein the vapor state with a counter-current stream of a con- Y trolled amount of cool hydrocarbons having the same number of carbonatoms tothe molecule as' said isomerized hydrocarbons* inV a catalyst Y separating zone to effect the condensation of sub-V stantially all of said entrained metal halide in the-.absence of anysubstantial condensation of hydrocarbons|` separately removing vapors comprising hydrocarbons free of any substantial trace of', metal halideiand liquid comprising hydrocarbons containingsubstantially all of said entrained metalhalide from said catalyst separating zone, and passing at least a part of said vapors from said catalyst separating zone to said fractionating zone.v c Y Y 12.. -In a catalytic hydrocarbon conversion process wherein normal and branched chain isomerizable saturated hydrocarbons -are converted 'to branched, and more highlyA branched vchain hydrocarbons respectively, having the same number of carboni-atoms lto the molecule as the hydrocarbons charged by contact at isomerizing conditions with a catalyst comprising a solution of aluminum chloride iii-antimony trichloride in a reaction zone and eiiluence from said reaction zone is passed to a fractionating zone, the steps which comprise contacting said reactor effluence comprising hydrocarbons and entrained catalyst components in the vapor state with a countercurrent stream of a controlled amount of cool hydrocarbons having the same number of carbon atoms to the molecule as said isomerized hydrocarbons in a catalyst separating zone to effect the condensation of substantially all of said entrained catalyst components in the absence of any substantial condensation of hydrocarbons, separately removing vapors comprising hydrocarbons free of any substantial trace of catalyst components and liquid comprising aluminum chloride dissolved in antimony trichloride from said catalyst separating zone, and passing at least a part of said vapors from said catalyst separating zone to said fractionating zone.

13. In a catalytic hydrocarbon conversion process wherein normal and branched chain isomerizable saturated hydrocarbons are converted to branched and more highly branched chain hydrocarbons respectively, having the'same number of carbon atoms to the molecule as the hydrocarbons charged, by contact at isomerizing conditions with a catalyst comprising aluminum chloride in a reaction zone and eilluence from said reaction zone is passed to a fractionating zone, the steps which comprise contacting said reactor efiiuence comprising hydrocarbons' and entrained aluminum chloride in the vapor state with a counter-current stream of a controlled amount of cool hydrocarbons having the same number of carbon atoms to the molecule as said isomerized hydrocarbons in a catalyst separating a zone to effect the condensation of substantially all of said entrained aluminum chloride in the absence of any substantial condensation of hydrocarbons, separately removing vapors comprising hydrocarbons free of any substantial trace of aluminum chloride and liquid comprising hydrocarbons containing substantially all of said entrained aluminum chloride from said catalyst separating zone, and passing at least a part of said vapors from saidcatalyst separating zone to said fractionating zone.

14. In a catalytic hydrocarbon conversion process wherein normal and branched chain isomerizable saturated hydrocarbons are converted to branched and more highly branched chain hydrocarbons respectively, having the same number of carbon atoms to the molecule as the hydrocarbons charged, by contact at isomerizing conditions with a' catalyst comprising a metal halide of the Friedel-Crafts type in a reaction .Zone and eilluence from said reaction zone is passed to a fractionating zone, the steps which comprise contacting said reactor eftluence comprising hydrocarbons and entrained metal halide in the vapor state with a counter-current stream of a controlled amount of cool hydrocarbons havingA the same number of carbon atoms to the molecule as said isomerized hydrocarbons in a catalyst separating zone to effect the condensation of substantially all of said entrained metal halide inthe absence of any substantial con'- densation of hydrocarbons, separately removing vapors comprising hydrocarbonsfree of any substantial trace of metal halide and liquid comprising hydrocarbons containingl substantially all of said entrained metal halide from said catalyst separating zone, passing said vapors from said catalyst separating zone to said fractionating zone, and passing at least a part of said liquid to said reaction zone.

15. In a catalytic hydrocarbon conversionv process wherein normal and branched chain isomerizable saturated hydrocarbons are converted to branched and more highly branched chain hydrocarbons respectively, having the same number of carbon atoms to the molecule as the hydro-` carbonsV charged by contact at isomerizing conditions with a catalyst comprising a solution of aluminum chloride in antimony trichloride in a reaction zone and eiiluence from said reaction zone is passed to a fractionating zone, the steps which comprise contacting said reactor eiliuence comprising hydrocarbons and entrained catalyst components in the vapor state with a counter-current stream of a controlled amount of cool hydrocarbons having the same number of carbon atoms to the molecule as said isomerized hydrocarbons in a catalyst separating zone to eiect the condensation of substantially all of said entrained process wherein normal and branched chain iso-p f merizable saturated hydrocarbons are converted to branched and more highly branched chain hydrocarbons respectively, having the same number of carbon atoms to the molecule as the hydrocarbons charged by contact at isomerizing conditions with a catalyst comprising aluminum chloride in a reaction zone and eilluence from said reaction zone is passed to a fractionating zone, the steps which comprise contacting said reactor eilluence comprising hydrocarbons and entrained aluminum chloride in the vapor state with a counter-current stream of a controlled amount of cool hydrocarbons having the same number of carbon atoms to the molecule as said isomerized hydrocarbons in a catalyst separating zone to effect the condensation of substantially all of said entrained aluminumV chloride in the absence of any substantial condensation of hydrocarbons, separately removing vapors comprising hydrocarbons free of any substantial trace of aluminumV chloride and liquid comprising hydrocarbons containing substantially all of said entrained aluminum chloride from said catalyst separating zone, passingvapors from said catalyst separat'-` Y. 19 ing zone to said fraction-ating zone, and passing at least a'part'of'said'liquid to said reaction zone.

'l'lfIn a, catalytic hydrocarbon fconver's'ion process wherein 'nor-mal and'branc'hed chain Yisr'o' merizable saturated'hydrocarbons are convertedtoV vbranched andi more highly branched chain hydrocarbons'respectively, having the saine number of Vcarbon atoms to the molecule as the hydrocarbons and' ent'rained metal halide inv the vapor staterwith a counter-current streamV of a controlledamount of cool hydrocarbons having the same number of carbon atoms to themmolecule as said isomerized `hydrocarbons in a catalyst sepairating zone to 4effect the condensation o'fsub-f f stantally all 'of said;ertl'ailedV metal halide Virl the absence of any "substantial condensationjof hydrocarbons, separately. removing vaporscofm' prising hydrocarbons Afree of any substantialt-raceY of'metal halide and liquid comprising lfiy'drdcary bons containing substantially all' of sa-id entrained metal halide from" said catalyst separat-l ing zone, passing' said vapors to said fractionat` Ving zone, and introducing'at least Va part of said liquid into said'reaction zone at a plurality of points along the length thereof.

SUMNER H'. MCALLISTER; JOHN ANDERSON. WIILIAM E.V Ross. 

